This invention relates to an electrical oscillator circuit comprising: a first subcircuit and a second subcircuit with a signal ground reference; a resonator unit comprised in the first subcircuit; an active device comprised in the second subcircuit connected to energize the resonator to provide an oscillating electrical signal transmitted as a differential signal via electrical conductors to the second subcircuit.
Moreover, the invention relates to an integrated circuit.
Electrical oscillators are used in various types of electronic equipment for instance in equipment where microprocessors and/or communications means are involved.
Especially in communications means the oscillator is a very central device for obtaining timing and modulation/demodulation. In order to obtain modern high speed communication, a stable and precise oscillator is required. Further, since small size and long duration battery operation is typically in demand the oscillator consequently has to be small sized and consume a minimum of electrical power.
An oscillator for the above devices fulfilling the demands is typically implemented by means of a crystal mounted on printed circuit board, connected to an active device, e.g. a CMOS transistor in an integrated circuit providing an oscillator signal to components or subcircuits in the integrated circuit by energizing the crystal to make the crystal generate the oscillator signal. This may provide for an accurate oscillator signal.
Ideally the whole oscillator should be placed in the chip, but this would require too much substrate area on in the integrated circuit. Preferably, the active device is within the integrated circuit where it can be implemented easily along with other active devices in subcircuits using the oscillator signal. Moreover, the least possible number of active devices should be used i.e. in order to minimize power consumption as indicated above.